Rotation mechanism for rock drills



April 3, 1928. 1,664,625

G. W. HULSHIZER ROTATION mabrmmsm FOR ROCK DRILLS Filed March 4. 1927 Q INVENTQR. GeogeWHu/siwg cu 31 a H/JATTO EY Patented Apr. 3, 1 928. I I UNITED STATES 1,664,625 PATENT OFFICE.

GEORGE W. HULSHIZER, OF STEWARTSVILLE. NEW JERSEY, ASSIGNOR T mGERSOLL- RAND COMPANY, OF JERSEY CITY, NEW JERSEY, CORPORATION OF NEW JERSEY.

ROTATION MECHANISM FOR ROCK DRILLS.

Application filed larch 4, 1927. Serial No. 172,731.

This invention relates to rock drills, but more particularly to a rotation mechanism for fluid actuated rock drills of the hammer type.

One object of the invention is to impart I a step by step rotative movement to the working implement, thus changing its position with respect to the work for'each successive blow of the hammer piston.

Another object is to insure prompt engagement and instant release between the movable and fixed elements of the rotation device at the most suitable period in the cycle of operations of the haimner'piston.

Other objects will appear hereinafter and to all of these ends the invent-ion consists of the combination of elements and arrangement of parts having the general mode of operation substantially as hereinafter described and claimed and illustrated in the accompanying drawing, in which.

Figure 1 is a longitudinal sectional view of a rock drill having the invention applied thereto. a I 1 Figure 2 is a transverse view taken through Figure 1 on the line 22 looking in the direction indicated bythe arrows,

Figure 3 is a similar view taken on the line 33 looking in the direction indicated by the arrows,

Figure 4 is a tion cup, and

Figure 5 is a similar view of the cover plate for the rotation cup.

Referring to the drawings, the invention is shown embodied in a rock drill having-a cylinder A, the front end of which supports a front head B. Near the front end of the cylinder A is bushing C which forms a closure for the cylinder and in this instance also acts as an abutment for the front head B. The rearward end of the cylinder A is suitably recessed to receive I a back cylinder washer D on which is seated a rotation ring a E disposed at the rearward end of the cylinder, and on this rotation ring is seated a back head F which forms a cover for the rearward end of the drill.

Disposed within the cylinder A is a reciprocatory hammer piston G having in this instance a forward fluted shank H which extends into the front head B to deliver blows to a working implement J, only the shank of which is shown. The extension H is adapted to cooperate slidably with the bushing C perspective view of a rotaand the flutes K of the shank H interlock slidably with a chuck bushing L carried by a chuck O which guides the working implement.

On the side of the cylinder A is a valve chest "P in which is formed a valve chamber Q. to accommodate a pressure distributing.

valve R. The valve R illustrated is of the oscillatory plate type pivoted on a pin S for controlling the inlet passages T and U leading from the rearward and front ends respectively of the valve chamber to the corresponding ends of the cylinder A.

Pressure fluid for actuating the piston may be conve 'ed from a suitable source of supply throng a connection V connected to the valve chest P and through a passage W leading from the connection to the valve chamber Q. In the present instance the exhaust of pressure fluid from the cylinder is efl'ected through a freeexhaustport X preferably located intermediate the ends of the cylinder and controlled by the piston G.

Suitable means are provided for imparting a step by step rotary movement to the working implement preparatory to the delivery of the blow of the hammer piston thereto. To that end a fluted rifle bar Y, preferably journalled in the back head F and the back 0 linde'r washer D, extends through the cylinder to. interlock slidably with a correspondingly fluted rifle nut Z screwed into the rearward end of the iston G. The rifle bar Y thus extends wit 1 its rearward end through a bore 6 in the rotation ring E and carries'on this portion an integral cam c. The cam 0 is preferably in the form of a parallelogram having two straight sides at, and two shorter end sides e which may be termed inclined or tapered sides.

Encircling the cam c is a cup 7 against the end wall of which the rearward end of the cam e is adapted to bear and a bearing surface is provided for the opposite end of the cam by a cover 9 abutting the back cylinder washer D. To the end that the cup f and the cover 9 may be suitably heldagainst relative rotation, the cup isin this instance provided wit-l1 radial notches h to receive lateral lugs j carried by the cover 9. Both the cup f and the cover are provided with radially extending recesses It so positioned with respect to the 1n 7' and the recesses k that they will be in a ignment when the cover and the cup are in theirassembled position.

Disposed loosely within the recesses 70 are rollers 0 adapted to be pressed against the rotation ring E by the tapered sides 6 of the cam 0. The rollers are of slightly smaller cross sectional area than the recesses is so that they may rotate freely in the recesses'. Such clearance in the'recesses, however, should be slight in order to prevent the rollers from moving in a tangential direction relatively to the cam upon the application of pressure thereto by the cam.

To the end that only limited rotative movement may occur between the cup f and the cam 0, thus at all times assuring the correct relative positions of the cam and the rollers 0, stops 7 in the form of pins are disposed on opposite sides of the cam 0, preferably near those ends of the cam which form the acute angle. The stops p are preferably spaced a slight distance'froin the operative position of the cam so that the cam may have limited movement in the direction of the stops from its engaging position. In the present instance the stops p are anchored at their ends in both the end wall of thecup f and also in the cover g. Sleeves q are disposed on the stops p partly to act as spacers for spacing the cover 9 with respect to the cup 7 and also to provide a renewable surface for the stops.

During the, operation of the device, as the piston starts rearwardly from the position illustrated in Figure 1, slight rotative move- 'ment is imparted to the rifle bar Y and, consequently, the cam d, due to the interlocking flutes of the rifle bar and the rifle nut TZ which tend to rotate the cam in a clockwise direction as Figure 1 is viewed from the left. As a result of such movement of the rifle bar, the rollers 0 will be jammed or pressed in a radial direction firmly against the wall of the rotation ring E, thus preventing any further rotative movement of the rifle bar during the rearward stroke of the piston. By thus holding the rifle bar immovable, the piston G will be caused to describe a partial revolution, and since the piston is held against rotative movement with respect to the working implement J, such rotative movement of the piston will be transmitted through the in terlocking parts connecting it with the work ing implement to change the position of the in the drill hole for the succeeding blow of the piston.

Upon reversal of the travel of the piston,

the rifle bar will be sufliciently rotated to enable the "cam a to release the rollers o and, during the forward stroke of-the piston, the rifle b'ar' together with the cu f may rotate freely, thus avoiding any riction which might hinder the speed of the piston.

In ractice, the present invention has been foun to function in an exceedingly eflicient manner. This is partly due to the total :ueeaeaa absence of friction of the parts comprising the rotation mechanism and in part due to the prompt-engagement and release between the rotative and stationary elements of the rotation mechanism. The parts comprising the device may be cheaply manufactured and may therefore be cheaply replaced in case of breakage or excessive wear.

Owing to the simplicity of construction of the device, these parts are capable of rendering service for an unusually great length of time since the cooperating, surfaces of the rollers and the rotation ring are smooth and unbroken, also the position of the rollers is constantly being changed so that instead of confining the wear to only a comparatively few cooperating surfaces, such wear may be distributed over a large area.

I claim:

1. In a rock drill having a cylinder provided with a piston, rotation mechanism for the piston comprising a rotation ring having a bore, a rifle bar in the bore extending into the cylinder to interlock slidably with the piston, means disposed loosely in the bore, means rotatable in the bore for guiding said means, and a cam in the second said means integral With the rifle bar for forcing the first said means firmly into en-' gagement with the rotation ring during one stroke of the piston, thus preventing rotation of the rifle bar and causing the piston to describe a partial revolution.

2. In a rock drill having a cylinder provided with a piston, rotation mechanism for the piston comprising a rotation ring, said rotation ring having a bore, a rifle bar interlocking slidably with the piston and extending through the bore. a cam on the rifle bar, means between the cam and the rotation ratchet holding the rifle bar against rotation during one stroke of the piston, thus causing the'piston to describe a partial revolution, and means rotatable in the bore for preventing tangential movement of the first-said means with respect to the cam upon the application of pressure thereto by the cam.

.3. In a rock drill having a e'linder and a piston, rotation mechamsm or the piston comprising a rotation ring seated on the cylinder, a rifle bar extending through the bore and interlocking slidably with the piston, a cam on the rifle bar disposed in the bore, a cup in the bore en'circlln the cam andv having recesses, and means isposed in the recesses adapted to be pressed against the rotation rin by the cam for holding the rifle bar against rotation during one stroke of the piston, thus causing the piston to describe a partial revolution to change the position of a working implement.

said rotation ring having a bore,

4. In a rock drill havinga cylinder and ton comprising a rotation ring seated on the cylinder, said rotation ring having a bore, a rifle bar extending through the rotation ring and the cylinder interlocking slidably with the piston, a cup rotatable in the bore having transverse recesses, rollers in the recesses, a cam on the rifle bar and disposed in the cupto actuate the rollers in a radial direction firmly against the rotation ring thus holding the rifle bar immovable during the rearward stroke of the piston and causing the piston to describe a partial revolution, and means carried by the cup for limiting relative rotation between the rifle bar and the cup.

5. In a rock drill having a cylinder and a piston, rotation mechanism for the piston comprising a rotation ring seated on the cylinder, said rotation ring having a bore, a rifle bar extending through the rotation ring and the cylinder interlocking slidably with the piston, a cup rotatable in the bore having diametricall opposed radially extending recesses, roliers in the recesses, a cam on the rifle bar disposed in the cup and having tapered sides to-press the rollers against the rotation ring and hold the rifle bar against rotation during the rearward stroke of the piston, thus enabling the piston to rotate on the rifle bar, a cover for the cup, and stops carried by the cup and the cover cooperating with the cam for holding the cup in operative position with respect to the cam.

6. In a rock drill having a cylinder and a piston, rotation mechanism for the piston comprising a rotation rin seated .on the cylinder, said rotation ring aving a bore,

a rifle bar extending through the rotation ringand the cylinder interlocking slidably with the piston, a cup rotatable in the bore having diametrically opposed transverse recesses, rollers in the recesses, a camon the rifle bar having tapered sides to press the rollers against the rotation ring and hold the rifle bar against rotation during the rearward stroke of the piston, thus enabling the piston to rotate on the rifle bar, a cover interlocked with the cup forming a bearing for one end of the cam, and stops anchored in the cup and the cover cooperating with the cam for limiting relative rotative movement between the cup and the cam.

7. In a rock drill having a cylinder and a piston, rotation mechanism for the piston comprising a rotation ring seated on the cylinder, said rotating ring having a cylindrical bore, a cup rotatable in the bore, a cover interlocking with the cup, said cup and cover having aligned transverse recesses, rollers in the recesses, a rifle bar extending through the rotation ring and the cylinder interlocking slidably with the piston, a cam on the rifle bar disposed in the cup, parallel tapered sides on the cam forcing the rollers firmly againstthe rotation ring to prevent relative rotation between the ratchet ring and the rifle bar during one stroke of the piston, thus causing the piston to describe a. partial revolution, and stops supported by the cup and the cover cooperating with the cam to limit relative rotation between the cup and the rifle bar.

In testimony whereof I have signed this specification.

GEORGE W. HU'LSHIZER. 

